${3 \div 0.3 = {?}}$
$ {3 \div 0.3 = 3 \div \dfrac{3}{10}} $ Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. $ {3 \div \dfrac{3}{10} = 3 \times \dfrac{10}{3}} $ $ {\phantom{3 \div \dfrac{3}{10}} = \dfrac{3 \times 10}{3}} $ $ {\phantom{3 \div \dfrac{3}{10}} = \dfrac{30}{3}} $ $ {\phantom{3 \div \dfrac{3}{10}} = 10} $